package com.atguigu.juc;

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * @author admin
 * <p>
 * 生产者与消费者案例
 */
public class TestProductorAndConsumerForLock {

    public static void main(String[] args) {
        ClerkForLock clerk = new ClerkForLock();

        ProductorForLock productor = new ProductorForLock(clerk);
        ConsumerForLock consumer = new ConsumerForLock(clerk);

        new Thread(productor, "生产者A").start();
        new Thread(consumer, "消费者B").start();

        new Thread(productor, "生产者C").start();
        new Thread(consumer, "消费者D").start();

    }
}

/**
 * 店员
 */
class ClerkForLock {

    private int product = 0;

    private Lock lock = new ReentrantLock();

    private Condition condition = lock.newCondition();

    /**
     * 进货
     */
    public void get() {

        lock.lock();

        try {

            /*
           为了避免 虚假唤醒 问题，应该总是使用在循环中
            */
            while (product >= 1) {
                System.out.println("产品已满！");

                try {
                    condition.await();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            System.out.println(Thread.currentThread().getName() + " : " + ++product);

            condition.signalAll();
        } finally {
            lock.unlock();
        }
    }

    /**
     * 缺货
     */
    public void sale() {

        lock.lock();

        try {

            while (product <= 0) {
                System.out.println("缺货！");

                try {
                    condition.await();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            System.out.println(Thread.currentThread().getName() + " : " + --product);

            condition.signalAll();
        } finally {
            lock.unlock();
        }
    }
}

/**
 * 生产者
 */
class ProductorForLock implements Runnable {

    private ClerkForLock clerk;

    public ProductorForLock(ClerkForLock clerk) {
        this.clerk = clerk;
    }

    @Override
    public void run() {
        for (int i = 0; i < 20; i++) {

            try {
                Thread.sleep(200);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            clerk.get();
        }
    }
}

/**
 * 消费者
 */
class ConsumerForLock implements Runnable {

    private ClerkForLock clerk;

    public ConsumerForLock(ClerkForLock clerk) {
        this.clerk = clerk;
    }

    @Override
    public void run() {
        for (int i = 0; i < 20; i++) {
            clerk.sale();
        }
    }
}
